While maintaining unity of wavelength of light emitted from a semiconductor light emitting element, decrease of light emission efficiency with an increase in environmental temperature is suppressed. A semiconductor light-emitting element includes: an n-cladding layer; a light emitting layer laminated on the n-cladding layer; and a p-type semiconductor layer laminated on the light emitting layer. The light emitting layer includes a first barrier layer to an eighth barrier layer and a first well layer to a seventh well layer, and a single well layer is sandwiched by two barrier layers. The first well layer to the fifth well layer have a common standard well thickness and a common composition, and the sixth well layer and the seventh well layer are set at a maximum well thickness larger than the common standard well thickness and have a composition whose band gap energy is larger than that of the common composition.